Funtenna is a software-only technique which causes intentional compromising emanation in a wide spectrum of modern computing hardware for the purpose of covert, reliable data exfiltration through secured and air-gapped networks. We present a generalized Funtenna technique that reliably encodes and emanates arbitrary data across wide portions of the electromagnetic spectrum, ranging from the sub-acoustic to RF and beyond.
The Funtenna technique is hardware agnostic, can operate within nearly all modern computer systems and embedded devices, and is specifically intended to operate within hardware not designed to to act as RF transmitters.We believe that Funtenna is an advancement of current state-of-the-art covert wireless exfiltration technologies. Specifically, Funtenna offers comparable exfiltration capabilities to RF-based retro-reflectors, but can be realized without the need for physical implantation and illumination.We first present a brief survey of the history of compromising emanation research, followed by a discussion of the theoretical mechanisms of Funtenna and intentionally induced compromising emanation in general. Lastly, we demonstrate implementations of Funtenna as small software implants within several ubiquitous embedded devices, such as VoIP phones and printers, and in common computer peripherals, such as hard disks, console ports, network interface cards and more.
Ang Cui is currently a PhD student at Columbia University in the Intrusion Detection Systems Laboratory. His research focuses on the exploitation and defense of embedded devices. Before starting his PhD, Ang worked as a security specialist within various financial institutions.